Phosphate assimilation by Chlorella and adjustment of phosphate concentration in basal medium for its cultivation

Abstract

Assimilation of phosphate by Chlorella pyrenoidosa was 0.81-8.1 mg PO(4)-P/g dry weight for heterotrophic cultures and 0.81-16.1 mg/g for mixotrophic cultures. Optimal carbon:phosphorous (C/P) ratios were 206:1-2060:1 and 103:1-2060:1 for heterotrophic and mixotrophic cultivations, respectively. These requirements for phosphate for growth of C. pyrenoidosa under either heterotrophic or mixotrophic conditions are much less (6.25-62.5 or 3.12-62.5-fold at 10 g glucose/l) than its concentration in basal medium.

Microalgae Cultivation on Anaerobic Digestate of Municipal Wastewater, Sewage Sludge and Agro-Waste

“…However, for both dA30W and dB5W, a low phosphate level may be the cause for the limitation in biomass accumulation. In both cases, the dilution applied led to a limitation of phosphorus availability, with phosphate concentrations of ~2.8 and 6 mg/L for d30W and dB5W, respectively; these concentrations are in the range where biomass accumulation is limited by phosphorus availability and close or even lower compared to the minimum phosphate concentration (4.56 mg/L) previously reported to be required in the case of Chlorella pyrenoidosa [57]. C. vulgaris and Scenedesmus I cells growing in dA30W or dB5w are thus under nutritional stress, inducing lipids and carotenoid accumulation, as previously reported.…”

Carotenoid production and change of photosynthetic functions in Scenedesmus sp. exposed to nitrogen limitation and acetate treatment

“…(identified by sequence analysis of the 18S ribosomal DNA, Canadian Phycological Culture Center, University of Waterloo) was grown in sterile BG11 liquid medium according to Rippka et al (1979). The medium containing 1.5 g L −1 (17.6 mM) of nitrate was found to have optimal content of N for algal growth (Qu et al 2008). Algae used in this experiment were cultured at 23°C in a 2-L bottle bioreactor with bubbling air and under continuous low light (50 μmol photons m −2 s −1 ).…”

Accumulation of intra-cellular polyphosphate in Chlorella vulgaris cells is related to indole-3-acetic acid produced by Azospirillum brasilense

“…Acquisition of phosphate by microalgae, either as planktonic cells or immobilized in polymers, as was shown in this study, is essentially similar to the process in higher plants [1,2,60,61]. Two options for active/inactive proton pumps are 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 proposed in plants.…”

“…This storage mechanism is found in marine and freshwater microalgae. Microalgae can accumulate more polyphosphate than is needed for immediate function of cells, [61,71,72]. The ability of microalgae to acquire phosphates in general and specifically the species used in this study is used as a biotechnological tool in tertiary wastewater treatment [50,69,73e75].…”